A wireless communication system, such as a third generation partnership project (3GPP) long term evolution (LTE) system, may provide a unicast communication service to a User Equipment (UE). In a unicast communication service, a base station transmits one data packet to a single User Equipment (UE). Alternatively or in combination, a wireless communication system may provide a group communication service to multiple UEs. In a group communication service, a base station transmits the same data packet to a group of UEs. For example, the group communication service can provide a Push to Talk (PTT) functionality. In a PTT service, one user in a group may push a button to transmit a communication, and other users in the group may receive the same communication simultaneously.
A wireless communication system may provide flexible modes of operation for a group communication service as the users and the environment they are operating in evolves. For example, an LTE or LTE_Advanced system supports broadband communication and, therefore, may support voice, video or, more general, data communication for a group communication service. Furthermore, an LTE or LTE_Advanced system can support users communicating with several groups at the same time in parallel. For example, the system may transmit a voice communication from a user to one group, and transmit a stream of video communication from the user to several other groups.